===================================================================
@@ -0,0 +1,20 @@
+// { dg-options "-std=c++1z" }
+
+template<typename T>
+ concept bool Eq() { return requires(T t) { t == t; }; }
+
+template<Eq T> struct Foo { };
+
+template<typename T>
+ struct S { // { dg-error "constraint failure" }
+ template<Eq U> friend class Bar;
+
+ friend class Foo<T>;
+ };
+
+struct X { };
+
+int main() {
+ S<int> si; // OK
+ S<X> sx;
+}
===================================================================
@@ -0,0 +1,33 @@
+// { dg-options "-std=c++1z" }
+
+template<typename T>
+ concept bool Eq() { return requires(T t) { t == t; }; }
+
+struct Nt {
+ template<Eq T> friend void f(T) { }
+} nt;
+
+template<typename T> struct S;
+
+template<Eq T>
+ void proc(S<T>*);
+
+template<typename T>
+ struct S {
+ friend bool operator==(S, S) requires Eq<T>() { return true; }
+
+ friend void proc<>(S*); // { dg-error "does not match any template declaration" }
+ };
+
+struct X { } x;
+
+int main() {
+ f(0); // OK
+ f(x); // { dg-error "cannot call" }
+
+ S<int> si;
+ si == si; // OK
+
+ S<X> sx;
+ sx == sx; // { dg-error "no match" }
+}
Added tests for constrained friends. No code, we already to the right thing. 2014-08-15 Andrew Sutton <andrew.n.sutton@gmail.com> Add tests for constrained friends. * gcc/testsuite/g++.dg/concepts/friend1.C: New. * gcc/testsuite/g++.dg/concepts/friend2.C: New. Andrew